Home, Sweet Nest

Nesting black-necked stilt (Himantopus mexicanus) ~ Brazoria Wildlife Refuge

Whether calling in flight, searching for food, or patrolling their territory on long, improbable legs, black-necked stilts always bring a smile. Their delicate, even fragile appearance is belied by their preferred habitats: fresh and saline marshes, mudflats, flooded agricultural fields, ponds, and drainage ditches.

During their mating season, which lasts from April through August, they construct ground nests near water, adding sticks, mud, grass, or shells to simple scrapes in the ground.

Both parents incubate three or four tan-colored eggs for 22-26 days; females often incubate by night, while both sexes take turns by day. Because even birds have to cope with the heat, on very hot days the parents will go to the water to wet their belly feathers before returning to the nest to cool the eggs.

After hatching, chicks run, walk, and swim as soon as their down has dried: usually within twenty-four hours. Their parents remove any tell-tale eggshells from the nest, and the chicks begin hiding in the water at night; both actions help to prevent predation by disguising their scent.

Nesting Pied-billed grebe (Podilymbus podiceps) ~ Brazoria Wildlife Refuge

Like the stilt, pied-billed grebes forgo trees for nesting purposes, but they prefer water instead of land. Shallow water will do, but depths greater than nine inches are best, since they allow the bird to approach or escape the nest underwater.

Usually found singly or in pairs around ponds and saltwater marshes, pied-billed grebes tend to dive at the slightest provocation, but they also possess the ability to squeeze air from their feathers and sink beneath the water’s surface without leaving so much as a ripple. Once underwater, they can stay submerged for some time,  swimming great distances to the safety of the reeds, or they can remain just below the surface, with only their eyes or nostrils visible.

Their tremendous swimming skills have a downside, of course. Barely able to walk on land, the grebes prefer to dive and swim when they sense danger, instead of flying to escape.

The water that protects them also facilitates construction of their nest platform: a dense mass of plant material that either floats or is anchored to standing vegetation, like the stems of bulrushes and water lilies. Both male and female participate in selecting the site and building the platform and nest, a bowl-like structure four to five inches in diameter and about an inch deep.

Eventually, both also join in incubating four to seven eggs for about twenty-three days, covering the eggs with nest material when they leave to feed. The young are able to swim almost immediately upon hatching, although I was surprised to learn that they sometimes ride on their parents’ backs like loons; adult pied-billed grebes have been known to swim underwater with their chicks on their backs. 

Ground-nesting birds are quite common, of course, but the black-necked stilt and pied-billed grebe are remarkably public about their nesting process. The next time I glimpse a nice, round clump of floating vegetation, or see a stilt just sitting around, I’ll take a closer look. There might be a new family waiting beneath the wings.

 

Comments always are welcome.

Truly Wild Flowers

Carolina larkspur (Delphinium carolinianum) ~ Rockport City Cemetery

If you think this larkspur seems unusual, you’re quite right. The mass of blooms, the unusually flattened stem, and the sheer size of the plant — nearly sixteen inches of floral exuberance — are clues that the plant is fasciated: a relatively uncommon condition that produces a variety of abnormalities in the plants it affects.

Sometimes, there is fusion or flattening in the plant — usually in its stem — that results in ribbon-like, coiled, or contorted tissue. Banding at the top of plants can cause them to increase in size and weight, while flowers and leaves growing on a fasciated plant’s flattened stems may be smaller than usual, or more more abundant, as with the larkspur I found at Rockport.

Fasciation has been attributed to a number of causes: genetic mutation, the presence of bacteria, fungi, or viruses; the activity of insects; or even weather conditions such as frost. Any physical damage to the growing point, or apical meristem, can lead to quirks in the production of new flowers, leaves, or stems.

Plant meristems usually produce the round or cylindrical stem we’re accustomed to seeing. In fasciated plants, the meristem flattens out and becomes elongated. Instead of producing a round stem, the mutation causes a flattened stem to develop.

A larkspur’s normal, cylindrical stem
The wide, flattened stem of the fasciated larkspur

Here, a fasciated and top-heavy Indian paintbrush (Castilleja indivisa) shows off its own flattened stem and remarkable size while lying on the ground; unbroken, it had been brought low by the weight of its own growth.

This Brazoria County paintbrush would do for a really large canvas

Here, the banding typical of fasciated stems is obvious.

Looking more like a chrysanthemum than an Indian paintbrush, this remarkable collection of individual blooms and colorful bracts had grown to be more than six inches in diameter.

It may be a bit of a commonplace, but it’s impossible to see these botanical anomalies without saying, “Fasciation is fascinating.”

 

Comments always are welcome.